Is it generally true that if a routing won't pop up in the online search results (despite all the airlines being searchable online) then an agent won't be able to book it?
I'm trying to book SFO-MLA. On July 4 there is saver business space on SFO-JFK-LHR, all on AA metal (AA 276 redeye on 7/4; AA 142 on 7/5, landing in LHR at 10:10 pm). This seems like the perfect thing to connect to BA 2646 (LGW-MLA) at 5:40pm on 7/6.
However, when I search SFO-MLA online, it only offers me AA276 connecting to BA 2272 (JFK-LGW landing at 10am on 7/6) to BA 2646 leaving at 5:40pm
I don't like this routing for a few reasons. First, I don't want to take BA for the TATL flight due to their ridiculous fuel surcharges. Also, I'd much rather have a 4 hr connection in JFK followed by an overnight in London rather than a non-overnight 15hr connection in New York followed by a 7hr connection in LHR.
Is there some married segment logic preventing me from booking this? Or something else? The routing seems to meet all the rules. I don't really understand how married segment logic affects connections between different airlines.